Gōki Daimonji commands Team Handsome as its leader while navigating his third year at Tokyo Metropolitan Harumi High School. He embraces a "Captain Pirate" persona, presiding over the card shop Voyage where he welcomes cardfighters of all abilities. His personality bursts with high excitability and lacks intellectual sharpness, yet he garners significant respect within the Vanguard community. A submissive streak emerges, particularly around his younger sister Nagisa, whom he dotes on excessively, fostering her spoiled nature. This devotion spills into her romantic life, leading him to mistakenly believe Kamui Katsuragi was involved with Aichi Sendou; Gōki consequently challenged Aichi to a cardfight to "win Kamui back" for Nagisa.
Competitively, Gōki steers Team Handsome through regional tournaments. They faced Team Q4, falling to Aichi Sendou and suffering elimination. In a later regional, semifinal defeat by Team Avengers dashed hopes of an Aichi rematch. During the Asia Circuit, Team Handsome vied for the national championship with Kamui Katsuragi temporarily bolstering their ranks. Observing Aichi's strategic use of Great Silver Wolf, Garmore's limit break later inspired Gōki to adapt similar tactics against Mitsusada "Koutei" Kenji.
Gōki fights exclusively with the Granblue clan, wielding a resurrection-based strategy that exploits the drop zone to relentlessly revive fallen units. This tactic enables aggressive guarding without permanent resource loss. A signature move involves superior calling his first vanguard, Guiding Zombie, to the front line on turn two for a free attack, later swapping it for resurrected powerhouses. He favors left-side placements and leverages superior ride lines to conserve card advantage while pressuring opponents with power-boosting units. His ultimate gambit combines soul-charging units like Rough Seas Banshee with King of Demonic Seas, Basskirk's megablast—demanding eight soulblast and five counterblast—to superior call up to five units from the drop zone, unleashing a devastating multi-attack barrage.
His primary deck, "Infinite Resurrection Hell," revolves around Basskirk, incorporating Captain Nightmist and Ruin Shade for power gains and field recursion. Inspired by Aichi's limit break approach, he later crafted a second deck, "Criminal Strom," utilizing Ice Prison Necromancer, Cocytus for endgame power surges and deploying Captain Nightkid as first vanguard to seed the drop zone and generate card advantage via Dancing Cutlass.
Visually, Gōki sports orange eyes and medium-length black hair, typically concealed beneath a red bandana. His pirate-themed attire features a brown vest over an orange and white torn shirt, a red sash belt, baggy tan pants, and knee-high brown boots. The kanji in his surname "Daimonji" (大文字) translates to "big/great" (大), "sentence/writings" (文), and "character/handwriting" (字).